====== Nomos Xi ======
{{wst>image_cr|Nomos|Xi|Nomos Xi (dial side)}}

The **Xi** (ξ) is an [[automatic]] [[worldtimer]] or [[GMT]] movement from [[Nomos]]. It was introduced in [[2011]] and phased out in [[2016]], replaced by the [[DUW 5201]].

===== Overview =====
The [[2005]] introduction of the [[Nomos Alpha|Alpha movement family]] was an important turning point for Nomos. Although based on the preceding [[Nomos 1 TSP]], it was largely constructed [[in-house]] rather than being a refinished [[ebauche]]. This was followed in [[2006]] by the Nomos Epsilon, the first Nomos movement with [[automatic winding]]. Both movements feature a gear train similar to the classic [[Peseux 7001]], but placed in a new enclosure based on the classic [[Glashütte]] [[three-quarter plate]] design. Nomos updated many of the components, adding [[hacking seconds]], and completely reworked the finishing with [[rhodium]]-plated surfaces, [[blued screws]], [[Glashütte Stripes]], and Glashütte [[solar grinding]] or [[Langeleist-Perlage]].

The automatic movements consist of [[Nomos Epsilon|Epsilon]], [[Nomos Zeta|Zeta]] (with [[date window|date]]), and Xi (with [[GMT]] or [[world time]] disc). All three movements measure 13¾ [[ligne]] (31 mm) in diameter, but Epsilon is thinnest at 4.3 mm. Like the [[date wheel]]s on the [[Nomos Beta]], [[Nomos Delta|Delta]], and Nomos Zeta|Zeta]], the Xi places the [[world time]] wheel outisde the periphery of the movement rather than stacked between the [[bottom plate]] and the [[dial]]. This allows the movement to be thinner than usual.

The [[world time]] function consists of an outer disc with city names or airport codes for each timezone and a [[24 hour]] wheel at 3 00 for "home time". It is operated by means of a [[pusher]] located at 2 00 and adjusted with a second pusher at 8 00 set flush with the case. Each time the main pusher is depressed, the central hour hand and location wheel advances by an hour. The second pusher advances the central hour hand separately from the location wheel, allowing it to be "calibrated" for the base timezone.

A direct successor to the Nomos Xi was introduced in [[2014]], the [[DUW 5201]] featuring the [[Nomos Swing System]]. The Xi calibre was phased out and retired in [[2016]].

This movement is officially named using the Greek letter "ξ", but Nomos often writes it as "Xi".

===== Applications =====
  * [[Nomos Tangomat GMT]] - A [[GMT]] window with airport codes at 9 00
  * [[Nomos Tangomat GMT Plus]] - A [[GMT]] window with simple "+/-" hour indicators at 9 00
  * [[Nomos Zürich Weltzeit]] - A full city wheel around the periphery of the dial

===== See Also =====
This movement is part of a family of Nomos movements produced since [[2005]]. The movement is partially made [[in-house]], though the [[assortment]] is supplied by a third-party. It was supplanted by the in-house [[Nomos Swing System]] family starting in [[2014]].

    * [[Nomos Alpha]] Hand winding
    * [[Nomos Beta]] Hand winding, date
    * [[Nomos Delta]] Hand winding, date, power reserve indicator
    * [[Nomos Epsilon]] Automatic
    * [[Nomos Zeta]] Automatic, date
    * [[Nomos Gamma]] Hand winding, power reserve indicator
    * [[Nomos Xi]] Automatic, GMT or world time
    * [[Nomos Alpha.2]] Hand winding, 2 hands

===== External Links =====
  * [[http://forums.timezone.com/index.php?t=tree&goto=6715286&rid=12189#msg_6715286|GMT Watches and the Nomos Zurich Weltzeit]]


<WRAP ud ud_mov>

**Description:**
  * [[Self-winding]] movement, bi-directional winding [[rotor]]
  * [[Escapement]] stone lever
  * [[Yoke winding system]]
  * [[Incabloc]] [[shock protection]]

**Functions:**
  * Hours, minutes
  * [[Small seconds]], date
  * [[Hacking seconds]]
  * [[World time indication]]

**Data:**
  * 13¾ [[ligne]]s
  * Ø 31 mm, H 5.7 mm
  * 26 [[jewels]]
  * 21,600 A/h
  * Bi-directional winding [[central rotor]] with rocker
  * [[Power reserve]] 42 hours

**Extras:**
  * [[Glashütte]] [[three-quarter plate]]
  * [[Glashütte]] click
  * [[Triovis]] [[precision adjustment]] (regulated in six positions)
  * [[Hairspring]] in [[Nivarox]] 1A
  * [[Blued]] screws
  * Ratchet and double wheel with [[Glashütte solar grinding]]
  * [[Rhodinated]] surfaces with [[Glashütte stripes]] and NOMOS-[[Perlage]]

**Production period:**
  * Production [[2011]]-[[2016]]
  * Successor [[DUW 5201]]
</WRAP>

{{tag>Movements Automatic_movements Worldtimer_movements Nomos_calibres}}